Improvement in seasoning and preserving wood



waited grates "gamut can.

CHARLES, MASSEY onnsson, or PHILADELPHIA, PENNSYLVANlA As- SIGN-careAMERICAN WOOD PROTECTION COMPANY.

Letters Patent No. 109,872, dated December 6, 1870.

IMPROVEI VIENT IN SEASONING AND FRESERVING WOOD.

The Schedule referred to in these Letters Patent and makiug part of thesame.

I, CHARLES MASSEY Cnnsson, M. D., of Philadelphia, county ofPhiladelphia and State of Pennsylvania, have invented an Improvement inSeasoning Wood and Protecting it from Decay, of which the following is aspecification;

Nature and Object of the Invention.

My invention consists in the application, substantially as describedhereafter, of liquids to timber, during the heating of the latter, forthe purpose of rendering less soluble those parts which are most liableto decay.

General Description.

The first resultof the application of heat to unseasoned timber is toconvert the surface-moisture into vapor; a' portion of this vaporescapes into the Y surrounding atmosphere, while the remainder passesinto the mass of the timber and is condensed, finally reaching thecentral portions, if the heat be long enough continued.

In this manner, the pores at the surface of the timber are deprived oftheir liquid contents and shrink, while those at the center are engorgedwith additional moisture and swell, so that the timberbe comes crackedin the outer portions, and this cracking is of greater extent when theprocess of vaporizing the water is a rapid one.

It is necessary, however, in order to insure perfect seasoning, that thewhole of the free water be expelled from the timber, and to do this itis essential that the whole mass of the timber be heated to or above 212Fahrenheit.

In my patent of July 7;, 1868, for seasoning timber, I treated thelatter in such a manner that while the timber was-being heatedthroughout its mass to 212 Fahrenheit, the surface was kept coated witha mixture of liquids of various volatilizing points, which liquids wereobtained from the condensation on'the surface of the wood of vaporsintroduced into the chamber in which the wood was being heated.

The effect of this treatment may be briefly described as follows:

In addition to the water volatilized a portion of another liquid wasalso volatilized, and condensed within the log with the vapors of water,while the sur face was wetted with a sufiicient amount of liquid notvolatilizable at the temperature to which the sur face was necessarilyexposed to heat the central parts, so that the poresat the surface weresufticien tly'filled to prevent cracking.

By observations upon the practical workings of the process and apparatusthen patented, I find that I can materially quicken-and chcapen theprocess by the cmployment'of an occasional shower-bath of or still.

the liquids of various volatilities, and in this way not only save theamountof fuel necessary for the volatilization of a portion of the oilsused to replace the water,v but also. secure a smhcient amount of liquidupon the upper surface of the timber treat-ed, whichthe use of vaporalone does not always secure.

To treat timber by this process, I placed: in a chamber with wallsso'constructed as to prevent, as far as possible, the outward radiationof heat, the

wood being stacked openly, to separate the surfaces of the pieces. i

Beneath the ceiling'of the chamber are secured perforated pipes, bymeans of which the warm liquids can besbowered upon the timber at properintervals.

That port-ion of the liquid not adhering to the surface orpenetrating'the timber, drops down to the bottom of the chamber, and-isthere treated by a coil of steam-pipes, or flows from thence back to aheater The excess of vapor and moisture driven from the wood may bepassed through a condensing apparatus for the recovery of the oils, andthe chamber must be so arranged with fines or steam-pipes'that thetemperature of the wood can be raised to the proper point.

The mixtnreof liquids employed should be composcd of those volatilizingbetween 180 and 300 or 320 Fahrenheit, and of such a nature that theywill not oxidize or promote oxidization, and will form gelatinousmixtures withthe gummy or albuminous matters of the wood.

The process of heating and showering should be continued until thecenter of the timber reaches 212 240 Fahrenheit as the timber will beless liable to crack when a longer time is employed in its treatrnent.

The time necessary to heat green oak timber to 212 Fahrenheit, thesurface being maintained at 280 or 290 l ahrenhcit, varies from an hourand a half to two hours per inch in timber of small dimensions, in achamber not only seven feet square, heated by steam-pipes, arrangedonthe bottom and sides.

After thecompletion of the operation, the timber I can be removed fromthe'chamber and allowed to cool.

This mode of treatment by occasional showers of liquids, is suited toordinary air-seasoning, but for In testimony whereof, I have signed myname to the preservation of timber, it is best to treat all of' 'thisspecification in the presence of two subscribing the albuminous matterto above 212"l alu'enheit, so witnesses. as to render them insoluble inwater. CHARLES M. CRESSON, M. I).

Clam Witnesses WM. A. STEEL, .TNO. B. HARDING.

The treatment, substantially as herein described, of timber with liquidapplications while the said timberis being heated. o

